Peripheral Nerve Stimulation

ABSTRACT

An apparatus for treating pain by electrical stimulation is disclosed. A lead is placed subcutaneously in the region of pain. The subcutaneous tissue is electrically stimulated to cause paresthesia. The method encompasses subcutaneous placement of an electrical lead near the region of pain and subsequent electrical stimulation of the tissue to cause paresthesia. In particular, an apparatus for treating intractable lower back pain using percutaneous electrostimulation techniques is disclosed.

This patent application is a continuation of U.S. patent applicationSer. No. 11/378,094, filed Mar. 17, 2006, which is incorporated hereinby reference in its entirety and which is a continuation of U.S. patentapplication Ser. No. 10/208,146, filed Jul. 30, 2002, which isincorporated herein by reference in its entirety and which is acontinuation of U.S. patent application Ser. No. 09/577,258, filed May22, 2000, now U.S. Pat. No. 6,505,075, which is incorporated herein byreference in its entirety and which claims priority to ProvisionalApplication 60/136,690, filed May 29, 1999, for which priority isclaimed.

FIELD OF THE INVENTION

This invention relates to a method for subcutaneously electricallystimulating peripheral nerves and in a particular embodiment relates toa method for subcutaneously electrically stimulating one or moreoccipital peripheral nerve to treat occipital neuralgia.

DESCRIPTION OF RELATED ART

Peripheral nerves are nerves in the body other than the nerves of thebrain or spinal cord. Peripheral nerve injury may result in thedevelopment of chronic intractable pain. Some patients proveunresponsive to conservative pain management techniques. PeripheralNerve Stimulation (PNS) has developed as a successful therapy for painmanagement when the pain is known to result from a specific nerve. PNSis based in part on the Melzack-Wall gate control theory of pain. Sweetand Wespic first used electrical stimulation of peripheral nerves in the1960s to mask the sensation of pain with a tingling sensation(paresthesia) caused by the electrical stimulation. Subsequentrefinements in the technology, surgical technique and patient selectionhave led to improved long term results.

PNS is an accepted alternative for those patients who have failed moreconservative pain management therapies. Clinical experience has shownthat when applied to appropriate patients by trained practitioners, PNScan reduce pain, reduce narcotic intake to manage pain and improve thepatient's activity levels and their quality of life. PNS has beenrecognized to have the following desirable characteristics:

-   -   The surgical procedure is relatively simple.    -   PNS is nondestructive. No known permanent surgical or chemical        interruption of nerve pathways occurs.    -   PNS is reversible. If the patient does not benefit, the device        can be turned off or removed. There are no known long-lasting        medical or surgical side effects.    -   Patients can be tested for response prior to implant of the        complete system.

Occipital nerves 2, 4 and 6 (FIG. 1) are peripheral nerves that exit thespinal cord at the C2 level of the cervical vertebrae and extend upwardgenerally along the back and back-sides of the head. The lesseroccipital nerve 2 extends upward and toward the sides of the head. Thegreater occipital nerve 4 extends upward toward the top of the head. Thethird occipital nerve 6 extends from near the neck around the back ofthe head toward the ear. Because of the location where the occipitalnerves leave the spinal cord, the occipital nerves pass from the spinalcolumn through muscle and fascia to the scalp.

Occipital neuralgia is a condition characterized by paroxysms of painoccurring within the distribution of the greater and/or lesser occipitalnerves. Occipital neuralgia has been described as a “jabbing” pain inthe area of the greater or lesser occipital nerve. The pain may radiatefrom the back or sides of the head toward the top or front of the head.Patients will vary in their reporting of this pain. It has beencharacterized in the medical literature as a unilateral or bilateralthrobbing pain that frequently radiates to the forehead and to thefrontal region (Stechison and Mullin, 1992) or as a lancinating painextending from the suboccipital region up to the top of the head. Thepain is less often described as including or consisting of a dullaching” (Sulfaro and Gobetti, 1995). Occipital neuralgia is oftenaccompanied by diminished sensation and sometimes extreme localizedtenderness over the applicable nerve.

Though known causes of occipital neuralgia include closed head injury,direct occipital nerve trauma, neuroma formation or upper cervical rootcompression (spondylosis or ligamentous hypertrophy), most patients haveno demonstrable lesion. An anesthetic block of the greater occipitalnerve can be used to confirm the diagnosis of occipital neuralgia (Khun,et al, 1997).

Traditional treatment options for intractable occipital nerve pain thathas proven to be resistant to medications usually involve chemical,thermal or surgical ablation procedures following diagnostic localanesthetic blockade. Surgical approaches include neurolysis or nervesectioning of either the occipital nerve in the occipital scalp or atthe upper cervical dorsal root exit zone (extradural). Forammaldecompression of C2 roots as well as C2 ganglionectomy have also beeneffective in reported cases.

Many patients with occipital neuralgia do not favorably respond to thesemedical treatments. Therefore, there is a need for an additionaleffective treatment of occipital neuralgia.

BRIEF SUMMARY OF THE INVENTION

A method for treating pain by subcutaneous electrical stimulation isdisclosed. A lead is placed subcutaneously over (superior to) aperipheral nerve that is causing pain. The nerve is electricallystimulated to cause paresthesia. As a result, the pain is masked. Themethod of the invention encompasses subcutaneous placement of anelectrical lead near any peripheral nerve causing pain and subsequentelectrical stimulation of the nerve to cause paresthesia.

In particular, a method for treating intractable occipital neuralgiausing percutaneous peripheral nerve electrostimulation techniques isdisclosed. The method involves a subcutaneous electrode placement at thelevel of C1 transversely across the base of the occipital nerve trunkand subsequent electrical stimulation of the occipital nerve trunk. Thisstimulation produces paresthesia and pain relief covering the regions ofoccipital nerve pain.

It is therefore an object of the invention to provide a method forsubcutaneously electrically stimulating nerves causing pain to createparesthesia.

It is another object of the invention to provide a method forpercutaneously placing leads subcutaneously to create paresthesia.

These and other object of the invention will be clear from the followingdetailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the occipital nerves.

FIG. 2 is a schematic view of the hardware used to practice theinvention of the present invention.

FIG. 3 is a perspective view of a screener device and a screening lead.

FIG. 4 is a top view of a permanent lead.

FIG. 5 is a perspective view of an implantable pulse generator (IPG).

FIG. 6 is a perspective view of an RF system receiver and an RF systemtransmitter.

FIG. 7 is a top view of an introducer needle curved to facilitateplacement of the permanent lead to treat occipital neuralgia.

FIG. 8 is a schematic view of the entry site used to implant a screeninglead or a permanent lead for treating occipital neuralgia.

FIG. 9 is a schematic view of the placement of the introducer needleprior to placing the screening lead.

FIG. 10 is a schematic view of the placement of the introducer needlewith the screening lead being inserted into the introducer needle.

FIG. 11 is a schematic view of dual leads placed to treat bilateralpain.

FIG. 12 is a perspective view of a patient prior to being implanted witha permanent lead.

FIG. 13 is a schematic view of the placement of the introducer needleprior to placing the permanent lead.

FIG. 14 is a schematic view of the placement of the introducer needlewith the permanent lead being inserted into the introducer needle.

FIG. 15 is a schematic view of the location of the subcutaneous pocketfor housing the loop of the permanent lead and the lead anchor.

FIG. 16 is a perspective view of a human torso and arm showing thelocation of the leads for two embodiments of the invention.

FIG. 17 is a perspective view of a human torso and arm showing the exitsites of the leads and preferred location for an IPG for the method ofFIG. 16.

FIG. 18 is a perspective view of a human leg showing the location of alead and IPG for an embodiment of the invention.

FIG. 19 is a perspective view of a human leg showing the location of alead and IPG for another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises a method of stimulating peripheralnerves. The method is preferentially accomplished in two stages: a testimplantation and screening stage and a permanent implantation of a leadand electrical stimulation system stage. The invention contemplatesusing, as shown in FIG. 2, a screening lead 10 (shown in detail in FIG.3), a screener device 12 (also shown in detail in FIG. 3), a permanentlead 14 (shown in detail in FIG. 4) and either an implanted pulsegenerator (IPG) 16 (shown in detail in FIG. 5) or an implanted RF systemreceiver 18 and its corresponding RE system transmitter 20 (shown indetail in FIG. 6).

The screening lead 10 and permanent lead 14 are preferably percutaneousleads chosen from the Pisces-Quad® family of quadripolar leads. Screenerdevice 12 is preferably a Model 3625 Screener or a Model 3628DualScreen® Screener. IPG 16 is preferably an Itrel® IPG. RE: systemreceiver 18 and RF system transmitter 20 are both preferably part of anRF stimulation system such as the X-Trell® or Matrix® RF StimulationSystems. Screening lead 10, permanent lead 14, screener device 12, IPG16, RE system receiver 18 and RF transmitter 20 are all available fromMedtronic, Inc. of Minneapolis, Minn.

The method for treating pain due to peripheral nerves involvessubcutaneous placement of a permanent lead 14 transversely across theperipheral nerve that is causing the pain. This peripheral nerve issubsequently electrically stimulated to cause paresthesia of the painfularea. The method also preferably involves placement of a screening lead10 and subsequent test electrical stimulation prior to placing thepermanent lead 14. Although the method preferably involves placing botha screening lead 10 and then a permanent lead 14, the method alsoincludes implanting just the permanent lead 14 as will be described indetail hereafter. For illustration purposes, the method for treatingpain due to peripheral nerves will be described with reference totreating occipital neuralgia by electrically stimulating the occipitalnerves.

One key to the technical success of this invention is the accurateplacement of the permanent lead 14. Because of the importance ofaccurate placement of the permanent lead 14, accurate placement ofpermanent lead 14 is facilitated by the placement of the screening lead10 and the subsequent test electrical stimulation. The steps in theinvention to percutaneously place a screening lead 10 to treat occipitalneuralgia will now be described in detail. These steps are given as thepreferred method of implementing the invention for most patients. It isrecognized, however, that the skilled physician will adapt the methoddescribed herein using his or her professional skill and judgment to theparticular circumstances of a particular patient. Further, although themethod of treating pain described in detail herein is specificallydirected to treating occipital neuralgia, unless otherwise specificallydirected, any reference to the occipital nerve or occipital neuralgiarefers as well to any peripheral nerve or neuralgias corresponding to aperipheral nerve, respectively.

The first step of the test implantation and screening stage is theimplantation of a screening lead 10. The method involves subcutaneousplacement of a screening lead 10 superficial to the fascia 34 or in thefascia 34 above (superior to) the occipital nerve causing pain andproximal to the level of detected pain. The first step in locating thearea to implant the screening lead 10 is to palpate the area of pain toidentify the specific nerve that is causing the pain. If it is confirmedthat an occipital nerve is causing the pain and the specific occipitalnerve has been identified, an introducer needle 22 is used to place thescreening lead 10.

The preferred embodiment for the introducer needle 22 is a Touhy needle.As shown in FIG. 7, the introducer needle 22 has a terminal end 24 thathas a beveled edge 26 and a proximal end 28 that includes a hub 30.Beveled edge 26 is a sharp edge that allows the terminal end 24 to bepushed through tissue. Hub 30 allows the physician to manipulate theintroducer needle 22. Hub 30 also has a notch 32 that is aligned withthe beveled edge 26 to indicate the orientation of beveled edge 26 tothe hub 30 by tactile sensation.

The introducer needle 22 is then subcutaneously placed superficial tothe fascia 34 or in the fascia 34 above (superior to) the nerve 36 thatis causing the pain. In the case of treating occipital neuralgia, theintroducer needle 22 is placed superficial to the fascia 34 or in thefascia 34 above (superior to) the occipital nerve that is causing thepain. Fascia 34 is a sheet of fibrous tissue that envelops the bodyunder the skin and also encloses the muscles. In the described method,the introducer needle 22 will be introduced superficial to the fascia 34or into the fascia 34 so that the introducer needle will be between thepatient's skin and muscle. The nerve causing the pain will be locatedwithin or under the musculature. In the case of treating occipitalneuralgia, the introducer needle 22 will be introduced superficial tothe fascia 34 or into the fascia 34 so that the introducer needle willbe between the patient's skin and the occipital nerve.

The introducer needle 22 is preferably introduced through a small stabwound “A” at the needle entry site (FIG. 8). Rapid needle insertion ispreferably used. This technique usually obviates the need for even ashort acting general anesthetic.

The introducer needle 22 is moved through the fascia 34 to a positionover the occipital nerve that is causing the pain (FIG. 9). When theintroducer needle 22 is in position above the occipital nerve, thescreening lead 10 is passed through the introducer needle 22 (FIG. 10)until the screening lead 10 is also in position above the occipitalnerve causing the pain. Then, the introducer needle 22 is removedleaving the screening lead 10 in place above the occipital nerve.

Single or dual quadripolar as well as single or dual octapolar screeningleads 10 may be used depending on whether the pain is unilateral (on oneside of the body only) or bilateral (on both sides of the body). Wherethe pain is bilateral and two screening leads 10 are used (FIG. 11),each screening lead 10 will be placed as described above.

Following placement of the screening lead 10 by the introducer needle22, the screening lead 10 is connected to the screening device 12, as iswell understood in the art. With the screening lead 10 in place asdescribed above and the screening lead 10 connected to the screeningdevice 12, the patient is electrically stimulated by the screening lead10 and screener device 12 to evaluate the screening lead 10 position andto develop optimal stimulation parameters. Stimulation is applied usingthe screener device 12 to select various electrode combinations,enabling the patient to report stimulation location, intensity andoverall sensation. This allows the physician to test the stimulation anddetermine optimum stimulation parameters prior to permanently implantingthe permanent lead 14 and the source of electrical stimulation pulses,either the IPG 16 or the RF system receiver 18. The effect of thisstimulation is determined and the parameters of stimulation adjusted foroptimal pain relief. It is preferred that the patient be awake and alertso that the patient will provide verbal feedback regarding paresthesiacoverage of the painful area to assist in determining the optimumstimulation parameter settings.

The following have been found to be typical ranges for stimulationparameters for screening by the screener device 12 and the screeninglead 10 to optimize paresthesia levels for pain coverage. Theseparameters can vary from patient to patient and may be outside theranges given here. Never-the-less, these representative values are givenfor the purpose of illustrating the invention and not for the purpose oflimiting the invention. Values for these parameters may be higher orlower than the values shown.

-   -   Amplitude: 0.5-4.0 volts    -   Pulse Width: 90-200 μsec    -   Rate: 50-400 Hz

If the patient reports muscle contractions (grabbing sensation) orburning, this usually indicates that the screening lead 10 is locatedtoo deep (anterior) in the subcutaneous tissue. It may also indicatethat the screening lead 10 is not positioned correctly above (superiorto) the nerve. It may be necessary to remove and reposition thescreening lead 10. If adjustment of screening lead 10 is necessary, thescreener device 12 is removed from the screening lead 10. Then, theposition of the screening lead 10 is adjusted and stimulation is testedagain for optimal pain relief. Adjusting the position of the screeninglead 10 may mean removing the screening lead 10 and re-implanting thescreening lead 10 according to the technique described above.

After good paresthesia coverage is obtained by manipulating theparameters of stimulation applied through screening lead 10,percutaneous testing wires can be externalized for the test stimulationperiod as is well understood in the art. This period is used to evaluatethe patient's response to stimulation before complete implantation ofall system components.

Alternately, once satisfactory paresthesia is confirmed, the screenerdevice 12 may be removed from the screening lead 10 and a source ofelectrical stimulation pulses such as the IPG 16 or RF system receiver18 is immediately implanted and attached to the screening lead 10.Hence, screening lead 10 in this embodiment becomes permanent lead 14.However, it is preferred that the patient use the implanted screeninglead 10 and screener system 12 for several days prior to implanting apermanent stimulation system.

Once the screening lead 10 has been appropriately positioned and tested,if satisfactory results are obtained, the method should proceed to the“permanent implantation of a lead and electrical stimulation system”stage. The steps in the invention to permanently implant a stimulationsystem will now be described in detail in connection with the treatmentof occipital neuralgia. As mentioned above, it is possible to implant asource of electrical stimulation pulses such as the IPG 16 or RE systemreceiver 18 and attached it directly to the screening lead 10 so thatscreening lead 10 becomes the permanent lead 14. However, the preferredembodiment of the invention contemplates removing the screening lead 10and replacing it with a permanent lead 14.

After it has been determined that the patient is receptive to painrelief from electrically stimulating the peripheral nerve causing thepain and the paresthesia associated with the electrical stimulation hasbeen maximized, the screener device. 12 is disconnected from thestimulation lead 10 and the screening lead 10 is removed. The patient isthen prepared for placement of the permanent lead 14 and the implantedpulse generator (IPG) 16 or implanted RE system receiver 18. The purposeof the “permanent implantation of a lead and electrical stimulationsystem” stage is to internalize (that is, implant) the permanent lead 14and either the IPG 16 or the RE system receiver 18. Therefore, thisstage includes implanting the permanent lead 14, neurostimulator (eitherIPG 16 or RE system receiver 18) and any extension sometimes used toconnect permanent lead 14 and either IPG 16 or RF system receiver 18 asis well understood in the art.

As stated above, one key to the technical success of this invention isthe accurate placement of the permanent lead 14. It is therefore crucialto the success of the invention to have a lead placement for thepermanent lead 14 that results in paresthesia that covers the patient'spainful area. Therefore, lead placement is preferably determined usingpatient feedback during intraoperative testing of the efficacy of thepermanent lead 14 placement and the stimulation parameters. Performingimplantation of the permanent lead 14 under local anesthetic allows forthis feedback.

A local anesthetic is preferably used in the area of the introducerneedle 22 entry site to ensure the patient is alert and able to respondduring the procedure. To help the patient relax, sedatives are alsopreferably administered intravenously. Prophylactic antibiotics can alsobe administered intravenously for protection from postoperativeinfection. As a result, the patient is preferably awake and alert duringthe placement of the permanent lead 14 and the subsequent teststimulation.

Where treating occipital neuralgia, the patient is preferably placed ina lateral position, or in a prone position with the head to the side, ona radiolucent table (FIG. 12). The patient is prepared and drapedaccording to standard surgical procedure. Fluoroscopy is used toidentify the location of the C1 vertebra. The location and midline ofthe C1 vertebra is marked on the patient's skin with a sterile marker.

A Touhy needle is preferably used as an introducer needle 22 tointroduce permanent lead 14. The introducer needle 22 includes a stylet42. The introducer needle 22 is manually gently curved by the physicianto conform to the contour of the patient's body above the peripheralnerve to facilitate placement of the permanent lead 14. Where theperipheral nerve is the occipital nerve, the introducer needle 22 ismanually gently curved by the physician to conform to the contour of thepatient's neck (FIG. 7) to facilitate placement of the permanent lead14.

A small stab wound “A” is made at the needle entry site (FIG. 8) at theC1 level. Using local anesthesia, a 2 cm. vertical skin, incision ismade in the patient's neck lateral to the midline of the spine at thelevel of C1. The introducer needle 22 is introduced into thesubcutaneous tissue, superficial to the fascia 34 and muscle layer butbelow the skin, without further dissection across the trunk of theoccipital nerves. These nerves are located within the cervicalmusculature and overlying fascia 34.

The physician then advances the introducer needle 22 transversely fromthe lateral incision point to and across the midline of the spine underfluoroscopic observation to the appropriate location above the trunk ofthe occipital nerve (FIG. 13). The beveled edge 26 of the introducerneedle 22 should face toward the front of the body (anterior). Theorientation of the beveled edge 26 can be verified by referring to thenotch 32 on the needle hub 30 of the introducer needle 22.

The curve of the introducer needle 22 may be checked, if desired, by thephysician by removing and re-inserting the needle stylet 42. A useful,curved introducer needle 22 is ensured if it is easy to remove andreinsert the stylet 42 within the introducer needle 22. If desired, anadditional check can be made by removing the stylet 42, then carefullyinserting the permanent lead 14 through the introducer needle 22 to justbeyond the beveled edge 26 of the introducer needle 22. If the curvatureof the introducer needle 22 is correct, the permanent lead 14 shouldpass easily to just beyond the beveled edge 26 of the introducer needle22. The permanent lead 14 is then removed and the stylet 42 re-insertedinto the introducer needle 22.

Once the desired position has been reached, the stylet 42 is removedfrom the introducer needle 22. The permanent lead 14 is slowly insertedthrough the introducer needle 22 until the distal tip 36 of thepermanent lead 14 just exits the introducer needle 22 (FIG. 14). Then,the introducer needle 22 is carefully removed over the permanent lead14. The permanent lead 14's placement is verified with fluoroscopy.Alternately, the introducer needle 22 can be partially removed. Thisallows the electrode contacts on the permanent lead 14 to be exposedwhile facilitating introducer needle 22 reinsertion if repositioning ofthe permanent lead 14 is needed. Fluoroscopy is used to ensure that allelectrodes of the permanent lead 14 are exposed. If necessary, theintroducer needle 22 may be adjusted to move the permanent lead 14 to alocation where the permanent lead 14 will optimally stimulate thetargeted occipital nerve(s).

If more than one permanent lead 14 is to be implanted, for example, oneach side of the midline to treat bilateral pain, the proceduredescribed above is repeated for each such permanent lead 14.

Following placement of the permanent lead 14 by the introducer needle22, the permanent lead 14 is again connected to the screening device 12,as is well understood in the art. This allows the physician to test thestimulation and confirm that paresthesia is obtained with the placementof the permanent lead 14 prior to permanently implanting the LPG 16 orthe RF system receiver 18. Since the patient is preferably awake andalert, the patient will provide verbal feedback regarding paresthesiacoverage of the painful area to assess the placement of the permanentlead 14.

If the patient reports muscle contractions (grabbing sensation) orburning, this usually indicates that the electrodes on the permanentlead 14 are too deep (anterior) in the subcutaneous tissue. It may alsoindicate that the electrodes are significantly above or below the C1landmark. It may be necessary to remove and reposition the permanentlead 14. If adjustment of permanent lead 14 is necessary, the screenerdevice 12 is removed from the permanent lead 14. Then, the position ofthe permanent lead 14 is adjusted and stimulation is tested again.

After good paresthesia coverage is obtained, the screener device 12 isremoved from the permanent lead 14. It is now possible to implant thesource of electrical stimulation pulses such as the IPG 16 or RF systemreceiver 18 and any extension sometimes used to connect permanent lead14 and either IPG 16 or RF system receiver 18 as is well understood inthe art. Internalization of the neurostimulation system for occipitalnerve stimulation preferably follows the protocol used for otherPeripheral Nerve Stimulation (PNS) indications as is well understood inthe art. Basically, the procedure involves creating a subcutaneouspocket 24 in tissue (FIG. 15), anchoring the permanent lead 14,implanting the IPG 16 or RF system 18, tunneling the permanent lead 14and connecting the permanent lead 14 to the IPG 16 or RF system 18 as iswell understood in the art.

The following have been found to be typical ranges for stimulationparameters applied to the permanent lead 14 to obtain optimumparesthesia levels for pain coverage to treat occipital neuralgia. Thesevalues can vary from patient to patient and may be outside the rangesgiven here. Never-the-less, these representative values are given forthe purpose of illustrating the invention and not for the purpose oflimiting the invention. Again, values for these parameters may be higheror lower than the values shown.

-   -   Amplitude: 0.5-4.0 volts    -   Pulse Width: 90-200 μsec    -   Rate: 50-400 Hz

These steps are given as the preferred method of implementing theinvention for most patients. It is recognized, however, that the skilledphysician will adapt the method described herein using his or herprofessional skill and judgment to the particular circumstances of aparticular patient.

A specific example of percutaneous nerve stimulation has been given fortreating occipital neuralgia. Although the method of treating occipitalneuralgia has been described in detail, the steps described can beadapted to treating other peripheral nerve applications as medicaljudgment and necessity require. Examples of other applications for thedescribed subcutaneous PNS technique include peripheral nerves in thehead and neck, trunk and limbs. Examples of neuralgias in the head andneck that can be treated by stimulating peripheral nerves include, butare not limited to, post herpetic neuralgia, chronic deafferentationpain, chronic peripheral nerve pain, post craniotomy pain and incisionalpain. For post herpetic neuralgia, the permanent lead 14 shouldpreferably be placed in the vicinity of the supraorbital nerve in theforehead area. For chronic deafferentation pain, the permanent lead 14should preferably be placed subcutaneously in the vicinity of thedeafferentation pain. For chronic peripheral nerve pain, the permanentlead 14 should preferably be placed proximal to any peripheral nervethroughout the body. For chronic post craniotomy pain, the permanentlead 14 should preferably be placed in the region of the craniotomyincision.

Examples of neuralgias in the trunk that can be treated by stimulatingperipheral nerves include, but are not limited to, clunial nerve pain,post herniorrhapy pain, localized low back or other spine pain andincisional neuroma pain. For clunial nerve pain, the permanent lead 14should preferably be placed over the clunial nerve in the buttock area.For post herniorrhapy pain, the permanent lead 14 should preferably beplaced subcutaneously in the region of the iliolinguinal nerve. Forlocalized low back or other spine pain, the permanent lead 14 shouldpreferably be placed in the vicinity of the localized area of pain. Forincisional neuroma pain, the permanent lead 14 should preferably besubcutaneously placed in the region of the incisional neuroma.

Examples of neuralgias in the limbs that can be treated by stimulatingperipheral nerves include, but are not limited to, stump neuroma pain,incisional scar pain, deafferention pain and chronic peripheral nervepain as for example with the median nerve or ulnar nerve. For stumpneuroma pain, the permanent lead 14 should preferably be subcutaneouslyplaced in the region of the neuroma. For incisional scar pain, thepermanent lead 14 should preferably be subcutaneously placed in theregion of the incision. For chronic peripheral nerve pain of the medialnerve or ulnar nerve, the permanent lead 14 should preferably be placedover the medial nerve 38 or ulnar nerve 40, respectively, as shown inFIG. 16. Here, the technique described above is applied to the placementof screening lead 10 and permanent lead 14 with the leads 10, 14 locatedabove (superior to) the desired peripheral nerve through medial nerveincision site 42 and ulnar nerve incision site 44, respectively. Oncethe permanent lead 14 is in place, the IPG 16 or RF system receiver 18is implanted as is well understood in the art (FIG. 17) and connected tothe permanent lead 14.

FIG. 18 shows the placement of a permanent lead 14 next to the sciaticnerve 46 in the leg. Permanent lead 14 is implanted as described abovethrough the sciatic nerve incision site 48. Placement of permanent lead14 and the subsequent electrical stimulation of the sciatic nerve 46could treat neuromas or chronic pain emanating from this peripheralnerve.

Further, FIG. 19 shows the placement of a permanent lead 14 next to aperipheral nerve 48 in the ankle, foot or other localized are of pain.Permanent lead 14 is implanted as described above through a peripheralnerve incision site 50. Placement of permanent lead 14 and thesubsequent electrical stimulation of the affected peripheral nerve 44could also treat neuromas in or around this peripheral nerve and alsochronic pain arising from this nerve.

The examples of the method of the invention shown in FIGS. 16-19 havebeen given to illustrate examples of peripheral nerves to which thepresent method could apply. The application of the present invention toother peripheral nerves with their corresponding maladies and neuromaswill occur to those skilled in the art. Conversely, once neurologicalmaladies or neuromas and their corresponding peripheral nerves have beenidentified, as will also occur to those skilled in the art, the presentinvention may be used to treat such maladies or neuromas. It is clearthat those skilled in the art will be able to practice the inventiondescribed above as applied to any peripheral nerve or to treat anyparticular neuroma by applying the disclosed method to its correspondingperipheral nerve.

The description contained herein is intended to be illustrative and notexhaustive. Many variations and alternatives will occur to one ofordinary skill in this art. All these alternatives and variations areintended to be included within the scope of the attached claims. Thosefamiliar with the art may recognize other equivalents to the specificembodiments described herein which equivalents are also intended to beencompassed by the claims attached hereto.

1-34. (canceled)
 35. A method of treating lower back pain comprising:(a) palpating the lower back of a patient to identify a painful area,(b) percutaneously placing at least one electrode in subcutaneous tissueproximate to said area of pain; (c) applying electrical stimulatingpulses from an implantable tissue stimulator to said electrode of afrequency, amplitude and duration sufficient to induce paresthesia; and(d) surgically implanting the tissue stimulator beneath the skin. 36.The method of claim 35 wherein the implantable tissue stimulatorcomprises an implantable pulse generator.
 37. The method of claim 35wherein the implantable tissue stimulator comprises a radio frequencysystem receiver.
 38. The method of claim 35 wherein the at least oneelectrode is on a test lead and further including before step (d)replacing the test lead with a permanent lead that includes astimulating electrode thereon.
 39. The method of claim 35 wherein the atleast one electrode is also entirely superficial to the muscle fascia insaid area.
 40. A method of treating lower back pain comprising the stepsof (a) palpating the lower back of a patient to identify a painful areasubserved by a peripheral nerve proximate to said area of pain; (b)percutaneously placing at least one electrode in subcutaneous tissue ata location entirely superficial to the nerve identified in step (a); (c)applying electrical stimulating pulses from an implantable tissuestimulator to said electrode of a frequency, amplitude and durationsufficient to induce paresthesia without an attendant burning orgrabbing sensation; and (d) surgically implanting the tissue stimulatorbeneath the skin.
 41. The method of claim 40 wherein the implantabletissue stimulator comprises an implantable pulse generator.
 42. Themethod of claim 40 wherein the implantable tissue stimulator comprises aradio frequency system receiver.
 43. The method of claim 40 wherein theat least one electrode is on a test lead and further including beforestep (d) replacing the test lead with a permanent lead that includes astimulating electrode thereon.
 44. The method of claim 40 wherein the atleast one electrode is also entirely superficial to the muscle fascia insaid area.